The present disclosure relates to a device and method for fixing a lamp part or component in the discharge tube of fluorescent lamps. This disclosure will have particular application with lamp parts or components made from shape memory alloys.
Lamps, and in particular fluorescent lamps or compact fluorescent lamps, include discharge tubes that contain a fill gas and related materials or lamp parts in a discharge space. Applying an electric potential provided by electrodes generates an arc and continued discharge therebetween to provide desired illumination. In many cases lamp elements such as mercury sources, getters, etc. need to be fixed inside the lamp. For example, positioning of a mercury source or mercury sources such as a main amalgam and/or auxiliary amalgam in the lamp affects lamp performance and thermal behavior. Fluorescent lamps that are dosed with an amalgam containing mercury have a long warm-up time. That is, the warm-up time is generally defined as that time period (measured from start-up or ignition) to reach 80% of a stabilized lumen output. Auxiliary amalgams are typically positioned on lead wires or mounts in order to reduce the warm-up time (see, for example, commonly owned U.S. Ser. No. 12/795,917, filed Jun. 8, 2010). The effect of the auxiliary amalgam on the warm-up time is limited, however, by the diffusion of mercury from the auxiliary amalgam into the discharge space. Diffusion lengths need to be reduced to improve the warm-up time decreasing effect of auxiliary amalgams. Incorporating additional auxiliary amalgams into the discharge space can decrease the diffusion length and the warm-up time. However, positioning amalgam sources at controlled locations in the discharge space, and assuring that the high-temperature amount comes in thermally controlled amalgam containers are accurately and effectively located where desired, are often difficult.
Accordingly, a need exists to improve positioning of amalgam sources, and likewise fixing other lamp components such as getters at desired locations within the discharge space. Similarly, there exists a need to provide a device and a method for reducing the length of diffusion of a fluorescent lamp without negatively affecting the quality or consistency of lamp illumination. Further, there exists a need for an efficient way to accurately position and immobilize auxiliary amalgams on mounts within a discharge lamp at a desired position to decrease diffusion length and warm-up time.